The Effect Of Exposure To Music On Spatial Learning And Memory In Rats

Music is an art form that conveys certain feelings and thoughts through harmonious sounds.Scientists have been investigating the effects of music on learning and memory.In 1993, Rauscher et al. found that listening to Mozart for 10 minutes (min) increased spatial learning performance in students lasting for 10-15 min (1).This finding was called the "Mozart effect" and was widely reported in the media.However, other researchers could not replicate the study, which led to controversy about its scientific validity.Rauscher et al. then identified an increase in spatial learning performance of children receiving music lessons for 6 months.Thus, it has been shown that the Mozart effect can occur not only in a short time but also in a long time period (2).Studies on rats and mice have also shown that listening to music can improve spatial learning (3,4).Additionally, these studies have found that music can increase levels of hippocampal cell proliferation (5), brain-derived neurotrophic factor (BDNF) (5), dopamine (6), and N-methyl D-aspartate (NMDA) receptor expression (7).The NMDA receptor (NMDAR) is a glutamate-gated cation channel that plays a key role in learning and memory (7,8).Studies have shown that NMDAR expression decreases in the auditory brainstem of rats with early postnatal deafness (8) and in the auditory cortex of rats with early auditory deprivation (9).This suggests that there may be a link between hearing and the NMDAR.Introduction: The increase in spatial learning and memory performance caused by music is called the 'Mozart effect'.Increased NMDA receptor (NMDAR) expression plays a role in this effect.Inhibition of NMDARs reduces Prepulse Inhibition (PPI) % values.The study aims to investigate the relationship between the Mozart effect and the NMDAR expression.Methods: Rats were divided into 6 groups.Three groups listened to white noise (WN) while the other three groups listened to Mozart (M).After the rats were performed in the 8-arm radial maze test, one of the three groups in both sound environments was chosen as the control group and was injected with saline.For the remaining two groups, one was injected with ketamine and the other was injected with MK-801.Then all groups underwent the PPI protocol.Results: It was found that Mozart groups had higher memory errors.The M+MK-801 group had lower PPI% values with 74 dB prepulse compared to the WN+Ketamine group.Conclusions: While the Mozart effect was not observed, on the contrary, a decrease in memory performance was detected.The effect of music on NMDARs may be at levels that do not change PPI values.Considering that parameters like the duration and intensity of music may cause stress, repeating the experiment with different conditions may provide new clues.